Ventilating means



F. L. BLADE VENTILATING MEANS Filed March 23, 1942 Feb. 8, 1944.

2 Sheets-Sheet 1 1 JIMfM 4;; "M, 44414 rm F. L. SLADE VENTILATING MEANSFeb. 8, 1944.

Filed March 23, 1942 2 Sheets-Sheet 2 Patented Feb. 8, 1944 UNITEDSTATES PATENT OFFICE VENTILATING MEANS Franklin L. Slade, Washington, D.0.

Application March 23, 1942, Serial No. 435,898

13 Claims. ('01. 98-40) This invention relates to apparatus for mixinggaseous fluids, and more particularly to ventilating means whereby freshor suitably conditioned air may be introduced into the atmosphere of anenclosure such as a room in a residence, office, or factory, or acompartment in a land or air vehicle or a marine vessel.

The general object of the invention is to provide a novel and improveddevice of the type described which is of economical construction, quietand efficient in operation, and susceptible of ready adaptation andmodification for various special uses.

In its preferred embodiments, the invention contemplates the provisionof one or more air outlet or diifuser members which are supplied withair from a duct to which they are connected either by means of branchconduits or by inserting the member in the main duct through an openingin the wall thereof. The diffuser member is in the form of asubstantially cylindrlcal drum having a closed end, an inlet opening inits circular wall, and an open end from which the air is discharged-withor without the deflecting action of suitable baifies-into the room.

The inlet opening in the side wall of the cylinder is positioned, withrespect to the supply ducts, for the introduction of the airdiametrically of the cylinder. A novel arrangement of a substantiallyspiral bafiie or guide walls is disposed within the cylinder forproviding a substantially circular passageway of gradually diminishingcross-section, by means of which the stream of air is caused to spillover the edge of the cylinder and diffuse into the enclosure equally inall directions radially of the outlet member. The whirling flow given tothe air stream also aids in the efficient mixing of the fluids, bygiving to the circular jet 2. tangential component; and, in certain ofthe practical embodiments of the invention, outlet baflles are providedadjacent the open end of the cylinder to divert or deflect the flow ofair to control the axial component of the stream. In other embodiments,the whirling stream of air is allowed to flow substantially freely fromthe periphery of the cylinder, and the open end may be merely covered bya grille.

The invention also contemplates the provision of a plurality of vanes orbafiie elements within the cylindrical outlet or diffuser, thusproducing several curved passageways within the device, all leading todifferent successive sectors of the rim. This arrangement is ofparticular advantage in cases where large diffuser members are employedor where the velocity of the air is high.

Another object of the invention is to provide in a diffuser of thistype, simple and effective means for regulating both the total flow ofair issuing from the unit and the proportioning of the flow around thecircumference.

Other objects and features of novelty will be apparent from thefollowing specification when read in connection with the accompanyingdrawings in which several embodiments of the invention are illustratedby way of example.

In the drawings:

Figure 1 isa somewhat diagrammatic plan view of an installation showingtwo of the novel outlet or diffuser members connected by means of branchconduits with a main supply duct;

Figure 2 is a view in side elevation of one of the diffuser units ofFigure 1;

Figure 3 is a view in horizontal cross-section of a diffuser membercomprising one embodiment of the invention;

Figure 4 is an exploded view in side elevation of the unit shown inFigure 3, illustrating the manner of assembly of the three principalparts of the device;

Figure 5 is a view in vertical section of the assembled unit;

Figure 6 is a horizontal sectional view similar to Figure 3, but showinganother embodiment of the invention;

Figure 7 is a similar view on a smaller scale of still anotherembodiment;

Figures 8 and 9 are views in bottom plan and vertical cross-section,respectively, of another form of diffuser;

Figure 10 is a horizontal sectional view other embodiment;

Figure 11 is a vertical sectional view of the unit shown in Figure 10;

Figure 12 is a view similar to Figure 10 but showing the guide bafflemember in an adjusted position;

Figures 13 and 14 are fragmentary views in vertical section of the rimof a diffuser such as that shown in Figure 11, illustrating the effectof varying the dimensions or configurations of the peripheral outletbafiie flange; and

Figures 15 and 16 are views in vertical longitudinal section andvertical transverse section, respectively, of a diffuser unit installedwithin a supply duct.

Before describing the various embodiments of the invention in. detail,it is well to indicate that of anthe diffuser outlets comprising thepresent invention may be installed within or adjacent either the top orbottom walls, or the side walls, of an enclosure into which a gaseousfluid is to be introduced, although in the principal application of theinvention the novel diffuser members will be installed in the top wallor ceiling of a room. Therefore, no limitation is to be drawn from theuse of the terms: vertical, horizontal, top, bottom, side, upper, lower,or the like, as used in the present description, since it is obviousthat the unit can be completely inverted or rotated through any angleand still perform its required functions.

In Figures 1 and 2 of the drawings, the outlet units are showndiagrammatically at 10 and these diagrams may represent any of thespecific embodiments of the invention described herein. In accordancewith this suggested method of installation, the main air supply duct Dis divided into a plurality of successive branch conduits C whichprovide communication between the duct D and the openings in the sidewalls of the diffuser members It. Each of the members it) comprisesessentially a cylindrical drum !2 preferably having a' flange l3 aroundthe margin of the lower open end thereof. In Figure 2 a flangeddeflector or bafile plate 45 is shown which characterizes one embodimentof the invention as will be presently described. By certain novelprovisions forming a basic conception in all of the embodiments of theinvention, the air or other gaseous fluid is given a circular movementwithin the drum and distributed equally around the periphery thereof. Inthe general view shown in Figure 2, the air is discharged through thebattle openin l6 between the flange or baffle plate l and the lowermargin of the outlet drum or cylinder I2.

One of the simpler forms of invention but one which includes the basicidea just mentioned, is illustrated in Figures 3, 4, and 5 of thedrawings. As most clearlyshown in the exploded view of Figure 4, theunit comprises essentially three separable elements. First thecylindrical casing [2 with its closed upper end portion l1 and its lowerperipheral flange l3. The cylindrical side wall l8 of the unit'isprovided with a substantially rectangular opening 29 in one side thereofwith which the branch conduit 0 connects. The second element of the unitis the substantially circular damper member 22 which, like the otherparts of the device, may conveniently be made of sheet metal. Thisdamper is preferably of a circular extent of somewhat more than 180 sothat i it may be sprung into position as shown in Figure 3 of thedrawings and be retained in snugly fitting contact with the innersurface of the wall iii of the cylinder [2. Obviously, the damper cannotbe of a greater circular extent than the extent of the side wall I8 lessthe width of the opening 20. The damper 22 is of slightly less heightthan the cylinder I2 and it is guided in its rotary movement between theend wall I? and the spaced lugs 24 which are formed or secured atintervals around the lower margin of the cylinder or drum l2. Forrotating the damper, there is provided a handle 25 which may besoldered, welded, or otherwise secured thereto, and it will be readilyapparent how the damper may be manipulated to move from the positionshown in Figure 3', in a clockwise direction so as to partially orcompletely close the opening 26.

The third important element of the unit comprises the vane or baffleassembly which may be drawings.

designated generally by the numeral l5. This element comprisesessentially a circular plate or disc 21, having the curved or flaredperipheral flange 28, this flange cooperating with the rim of the lowerend of the cylinder I2 and its flange iii, to provide an annularoutwardly opening slot 16 through which the air is delivered. Preferablythe element I5 is designed to carry the inner substantially spiralbaflle element 30 which is disposed vertically of the cylinder l2 and issuitably secured to the disc 27 as by soldering or welding as indicatedat 3| in Figure 5. The curved spiral bafile or vane 3ilwhich may beeither a solid element or formed of sheet material as shown,is providedwith a concave portion 32 terminating in a wing 33 which contacts thewall i8 of the cylinder l2 adjacent one side of the opening 20. Furtherportions of the baffie element 39 are convex as indicated at 34 and thecurvature is such that the wall provided by the bafile member constantlyapproaches the side wall E8 of the cylinder so as to provide asubstantially circular passageway 35 of gradually diminishingcross-section throughout the peripheral extent of the interior of theunit. The diminution of cross-section of the passageway is substantiallyconstant. In this way the stream of air entering from the duct orconduit (2 through the opening 2|] and passing around the interior ofthe cylinder is gradually crowded out of the diffuser over the rim,thereof and out of the slot l6 between the rim and the bafile 28. Thus,it will be seen that the device is so designed that an even distributionof air is provided throughout the entire periphery of the arrangement.This even distribution or flow of air is also substantially maintainedadjacent the edge of the device just beneath the duct C and its o gening20 at the left-hand side of Figures and Any suitable means may beprovided for securingthe several elements of the unit together in theirpositions for proper functioning, but one simple and effective method isillustrated in the A bolt or rod 38 passes through centrally disposedopenings in the top end I! of the cylinder and the plate or disc 21. Anut 39 is applied to the threaded lower end of the bolt 38 and theelement I5 is thus securely attached to the cylinder l2.

The general direction of flow of the stream'of air through the annularslot I6 is radial. However, the whirling set up within the diffuser addsa tangential component to the outflowing stream, and obviously once thestream has passed the outer peripheral edge of the flared flange 28 thebody of air will expand downwardly with a slight axial component.

Optionafly the modified forms of the diffuser unit shown in Figures 6and '7 may be used. In these arrangements, the same sort of cylinder I2is employed either with or without the lower baflie element 15.Similarly the main baiiie member 30 is used and occupies substantiallythe same position as in the case of theenibodiment first described.However, in the arrange ment shown in Figure 6 an additional baiile orvane 40 is provided, which vane maybe secured to the member l5 asdescribed in the earlier embodiment in connection with bafile 30,01 itmay be soldered or welded to the top I! of the cylinder l2. This vane 40has its advanced vertical edge 4| disposed so as to divide the incomingstream of air at the opening 20 into two substantially equal parts. Theconfiguration of the vane 50 approximates the curvature of the portions32, 33 and the first part of portion 34 of the wall of baflle 30 andlies substantially parallel therewith. The vane 4|] terminates in a rearvertical edge 42 at a point approximately half-way around the cylinder.This arrangement thus provides an outer diminishing passageway 45 bywhich the air is caused to flow over the rim of the cylinder and out ofthe slot I6 during the first half of the flow around the cylinder, whilethe other body of'air is caused to flow through the inner passageway 46without diminution of volume until the edge 42 of the vane 40 isreached. Thereupon the air from the passageway 45 flows into the mainundivided passageway and, due to the diminishing cross-section, thisstream of air is diverted out wardly through the remainder of the slotHi.

In the embodiment shown in Figure "I, the incoming stream of air isdivided into three parts as by means of the baffles 40A and 4013, thebatfle MIA terminating approximately one-third of the way around thecylinder and the baffle or vane 50B extending for about two-thirds ofthe circumference. The vane 40A gradually approaches the margin of thecylinder and functions to squeeze the air from the channel 31 outthrough the slot I6; the air from the channel 4B is carried around forabout one-third of the periphery of the cylinder with undiminishedvolume and is distributed during the second approximately one-third ofthe travel, by the approach of the bafiie 4013 to the wall I8 of thecylinder during this sector. The inner channel 49 is of substantiallyundiminished cross-section until the last sector is reached, whereuponthe contour of the inner baflle or vane 30 causes the air to bedistributed through the slot IE along this sector. The arrangementsshown in Figures 6 and 7 are particularly useful in connection withoutlet drums of larger sizes.

In cases where the downward penetration of the introduced air into thehabitable portions of the room is not objectionable, the flange plate Imay be omitted, and if desired the open end of the cylindrical diffusermember may be covered by a grille such as shown at 50 in the embodimentshown in Figures 8 and 9. The grille 50 may be provided with anunperforated rim 5| secured as by means of the bolts 52 to the flange I3of the cylinder I2. The grille 50 is provided with a plurality ofperforations 53 through which the air may flow. The damper 22 is appliedas usual and may be retained either by means of the lugs 24 as in theembodiments previously described or it may be held in place by thegrille 50. In either event, however, the operating handle 25 of thedamper projects through an arcuate slot 55 in the grille 50 and isguided for limited movement by said slot. In this case the spiral baiileelement may be conveniently secured to the top end I! of the cylinder asindicated at 56, or if desired it may be suitably secured to the grille50 for installation and removal therewith. With this arrangement, theannular whirling stream of air will issue from the marginal edge of thecylinder as indicated by the arrows 51 and will have a much greaterdownward component than in the embodiments in which the bafile plate I5is employed.

One of the most important embodiments of the invention is illustrated inFigures 10-12 inclusive of the drawings and will now be described. Thecylinder I2 with its flange I3 and inlet opening 20 may be constructedas in the embodiments previously described, and the damper 22 may besupported by the guide lugs 24 and operated by a handle 25 as in theother modifications. However, in this embodiment the flanged baiileplate H5 has a slightly smaller disc portion I21 which is disposedwithin the cylinder I2 at a point spaced from the plane of the open endof the cylinder. In this arrangement, the vane I30 is somewhatdiminished in height and is also of a diiIerent construction adjacentthe inlet end of the difiuser. This difierence resides in the omissionof the tongue 33, the vane member I30 in this instance comprises merelythe concave portion 32 and the convex portion 34, these portionsadjoining at a rather acutely curved edge or corner 59, leaving anopening 60, between the wide entry portion of the channel I35 and theattenuated terminal portion thereof.

The baffle or vane unit II5I30 may be adjustably secured to the topplate I! of the drum or cylinder I2 by means of the bolt I38 or anysuitable equivalent means. Assuming that the original diminishing of thevane I30 has been executed accurately in accordance with the pressureand volume of .the air supplied and the size of the outlet cylinder, theapproximate proper position of the vane I30, in order to insure an equalflow of air throughout the margin of the difiuser, would be as indicatedin Figure 10 of the drawings. However, in case of fluctuations in theair supply or any slight unavoidable departures from the properconfiguration of the parts, a suitable rotative adjustment of the vaneor baffle member may be made as suggested in Figure 12 of the drawings,where the bafl'le member has been moved to some extent in a clockwisedirection.

Such an adjustment of the vane or bafile element may also be made inorder to purposely cause an unequal distribution of aircircumferentially of the diffuser as, for example, when it may bedesirable to deliver more air upon one side of the device than theothers.

As indicated in Figures 13 and 14, the baffle flange 28 of the membersI5 or I I5 may be shortened to any desired extent in order to vary theamount of the axial component of the flow of air. Obviously, in the caseof the difiusers shown in Figures 5 and 11, the fiat annular stream ofair flowing through the slot I6 has very little divergence, thisdivergence being measured in Figure 11 by the angle a. In Figure 13 thehorizontal portion of the flared flange or bafile 28A has been shortenedand the air will flow over the edge of the flange and the angle ofdelivery of the air will be somewhat greater as indicated at 8. InFigure 14 the flange 28B is shown as very considerably shortened and theextent of the stream of air is measured by the wider angle designated'y. 7

Instead of providing branch conduits C to connect the diffuser units [0with the main conduit D, the units themselves may be set in openings inthe main conduit as shown in Figures 15 and 16 of the drawings. The mainconduit is represented in these figures at D' and is provided with acircular opening in the bottom wall indicated at 05. The flange l3 ofthe unit II] may be suitably secured to the bottom wall of the conduitand the baffle unit I5 projects downwardly into theenclosure. In thiscase no branch conduit is necessary and the opening 20 in the cylinderI2 is disposed so as to face the oncoming stream of air or other gaseousfluid indicated by thearrows 66. Cylinder I2 thus acts as a scoop. forcatching a portion of the air in the conduit, diverting it through thedevice and delivering it tothe room in the whirling annular stream asalready described. or course, any of the embodiments described in detailherein may be applied tothe main duct in the manner suggested in Figures15 and 16, whether or not the baille plate I5is employed, and whateverthe arrangement of vanes or bafiles within the. unit.

Obviously, within the scope of the. invention, the bafile element may beconstructed with an opposite curvature from thatillustrated in thedrawings and applied to the other edge of the inlet opening 20, so thatthe air swirls around the channel in a clockwise direction instead ofcounter-clockwise. This, of. course, requires a reversal of thedirection of movement of the damper from that described, especially inthe case ofv the embodiment shown in Figure 3.

It is understood that various other changes and modifications may bemade in the embodiments illustrated and described herein withoutdeparting from the scope of the invention as defined by the followingclaims.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and aninlet opening in its side wall, means for directing flow ofair into said opening and a centrally disposed baille element withinsaid member and directly behind said opening, said element providing agenerally spiral interior wall surface perpendicular to said closed endand forming with the closed end and side wall of the cylindrical membera substantially annular channel which gradually diminishes incross-sectional area from a maximum at the inlet opening of thecylindrical member, around the member, to a minimum at a point adjacentsaid opening, whereby the air will be dischargedover the rim of the openend of the cylindrical member substantially equally at all points aroundsaid rim.

2. In a ventilating system or the like, a diifuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening in a direction diametrically of said cylindricalmember and a centrally disposed baffle element within said member anddirectly behind said opening, said element providing a, curved interiorwall surface perpendicular to said closed end and spaced apart from theside wall of the cylindrical member, the spacing gradually diminishingfrom a maximum at the inlet opening around the interior of the cylinderto a minimum at a point at one side of said inlet opening, whereby theair will be discharged over the rim oi the open end of the cylindricalmember substantially equally at all points around said rim.

3. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair intosaid opening and a centrally disposed bafileelement providing agenerally spiral, curved, interior wall surface perpendicular to saidclosed end, one portion of said element disposed adjacent one margin ofsaid inlet opening, the bailie wall surface extending from said portionwith an outwardly concave configuration in front of said inlet openingand thence with an outwardly convex configuration facing the side wallof the cylindrical member, and continuing around the center of thecylinder and gradually approaching the circumference to a point adjacentthe initial portion of said baflle wall near the edge of the inletopening, the substantially annular space between the baffie wall and theouter wall of the cylinder gradually diminishing in cross section,wherebythe air will be discharged substantially equally at all pointsaround the peripheral rim of the open end of the cylindrical member.

l. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening and a centrally disposed bafile element providinga generally spiral interior wall surface perpendicular to said closedend, one portion of said element contacting the wall of said cylindricalmember adjacent one margin of said inlet opening, the baffle wallsurface extending from said portion with an outwardly concaveconfiguration in front of said inlet opening and thence with anoutwardly convex configuration facing the side wall of the cylindricalmember, and continuing around the center of the cylinder and graduallyapproaching the circumference to a point adjacent the initial portion ofsaid baffle wall near the edge of the inlet opening, the substantiallyannular space between the baffle wall and the outer wall of the cylindergradually diminishing in cross section and terminating at said point,whereby the air will be discharged over the rim of the open end of thecylindrical member substantially equally at all points around saidrim.

5. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollowcylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening in a direction diametrically of said cylindricalmember and a centrally disposed bafile element providing a curvedinterior wall surface perpendicular to said closed end and spaced apartfrom the side wall of the cylindrical member, the spacing graduallydiminishing from a maximum at the inlet opening around the interior ofthe cylinder to a minimum at a point at one side of said inlet openingwhereby the air will be discharged over the rim of the open end of thecylindrical member substantially equally at all points around said rim,and means for securing said baflle element in selected rotative adjustedpositions with respect to said cylindrical member and to the inletopening, to vary the distribution of air discharged over said rim.

6. In a. ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, saidunit comprising, in combination,a hollow cylindrical member having a closed end and an open end, and aninlet opening in its side wall, means for directing flow of air intosaid opening and a centrally disposed baiile element providing a curved,endless interior wall surface perpendicular to said closed end, onepoint on the wall surface'of said element disposed adjacent one marginof said inlet opening, the baffle wall surface extending from saidportion with an outwardly concave configuration in front of said inletopening and thence with an outwardly convex configuration facing theside wall of the cylindrical member, and continuing around the center ofthe cylinder and gradually approaching the circumference to a pointadjacent the initial portion of said baffle wall near the edge of theinlet opening, the substantially annular space between the bafile walland the outer wall of the cylinder gradually diminishing incross-section, whereby the air will be discharged over the rim of theopen end of the cylindrical member substantially equally at all pointsaround said rim, and means for securing said baflle element in selectedrotative adjusted positions with respect to said cylindrical member andto the inlet opening, to correct or vary the distribution of airdischarged over said rim.

7. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical meme br having a closed end and anopen end, and an inlet opening in its side wall, means for directingflow of air into said opening, a centrally disposed baffle elementwithin said member and directly behind said opening. said elementproviding a generally spiral interior wall surface perpendicular to saidclosed end and forming with the closed end and side wall of thecylindrical member a substantially annular channel which graduallydiminishes in cross-sectional area from a maximum at the inlet openingof the cylindrical member, around the member, to a minimum at a pointadjacent said opening, whereby the air will be discharged over the rimof the open end of the cylindrical member substantially equally at allpoints around said rim and a cover for the greater portion of the openend of said cylindrical member, the margin of said cover being spacedfrom the peripheral rim of the open end of said cylindrical member toprovide an annular outlet opening for the air.

8. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening, a centrally disposed bafile element within saidmember and directly behind said opening, said element providing agenerally spiral interior wall surface perpendicular to said closed endand forming with the closed end and side wall of the cylindrical membera substantially annular channel which gradually diminishes incross-sectional area from a maximum at the inlet opening of thecylindrical member, around the member, to a minimum at a point adjacentsaidopening, whereby the air will be discharged over the rim of the openend of the cylindrical member substantially equally at all points aroundsaid rim and a cover for the greater portion of the open end of saidcylindrical member, the margin of said cover being spaced from theperipheral rim of the open end of said cylindrical member to provide anannular outlet opening for the air, said cover being provided around itsperiphery with a curved flange for deflecting the air in radialdirections.

9. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening in a direction diametrically of said cylindricalmember, a centrally disposed baflie element providing a curved interiorwall surface perpendicular to said closed end and spaced apart from theside wall of the cylindrical member, the spacing gradually diminishingfrom a maximum at the inlet opening around the interior of the cylinderto a minimum at a point at one side of said inlet opening whereby theair will be discharged over the rim of the open end of the cylindricalmember substantially equally at all points around said rim, and meansfor securing said baflie element in selected rotative adjusted positionswith respect to said cylindrical member and to the inlet opening, tocorrect or vary the distribution of air discharged over said rim and acover adjustably secured to said cylindrical member and adapted tooverlie the greater portion of the open end thereof, the margin of saidcover being spaced from the peripheral rim of the open end of saidcylindrical member to provide an annular outlet opening for the air,said baffle element being secured to said cover, whereby rotation of thelatter will effect the desired rotatable adjustment of the former.

10. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening, a centrally disposed bafile (element providing agenerally spiral interior wall surface perpendicular to said closed endand forming with the wall and the bottom of the cylindrical member asubstantially annular channel which gradually diminishes incrosssectional area from a maximum at the inlet opening the cylindricalmember, around the member, to a minimum at a point adjacent saidopening, whereby the air will be discharged over the rim of the open endof the cylindrical member substantially equally at all points aroundsaid rim and a bafiie plate disposed perpendicularly to the bottom ofsaid cylindrical member and between the centrally disposed baflleelement and the outer wall of the cylinder, said bafile plate extendingfor a portion only of the circumference of the cylinder and conformingto the curvature of the surface of the bafile element to which it isadjacent, whereby the channel is divided for a portion of its lengthinto two channels the inner one being of substantially the samecrosssectional area throughout its length while the outer one diminishesgradually to effect the discharge of air as described.

11. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening in a direction diametrically of said cylidricalmember, a centrally disposed balile element within said member anddirectly behind said opening, said element providing a curved interiorwall surface perpendicular to said closed end and spaced apart from theside wall of the cylindrical member, the spacing gradually diminishingfrom a maximum at the inlet opening around the interior of the cylinderto a minimum at a point at one side of said inlet opening, whereby theair will be discharged over the rim of the open end of the cylindricalmember substantially equally at all points around said rim, a cover forthe greater portion of the open end of said cylindrical member, themargin of said cover being spaced from the peripheral rim of the openend of said cylindrical member to provide an annular outlet opening forthe air and an arcuate damper fitted to the interior surface of thecylindrical member and extending around the latter for more than 180degrees, and means for rotatably adjusting said damper to partially orfully close the inlet opening, said adjusting means comprising amanually operable member eXtending through the annular air dischargespace.

12. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening in a direction diametrically of said cylindricalmember, a centrally disposed bafiie element within said member anddirectly behind said opening, said element providing a curved interiorwall surface perpendicular to said closed end and spaced apart from theside wall of the cylindrical member, the spacing, gradually diminishingfrom a maximum at the inlet opening around the interior of the cylinderto a minimum at a point at one side of said inlet opening, whereby theair will be discharged over the rim of the open end of the cylindricalmember substantially equally at all points around said rim, and anarcuate damper fitted to the interior surface of the cylindrical member,a plurality of lugs on the wall of said cylinder adjacent the open end,said damper being guided between said lugs and the bottom of saidcylindrical member, and means for rotatably adjusting said damper topartially or fully close the inlet opening.

13. In a ventilating system or the like, a diffuser unit for introducingair into a room or other enclosure, said unit comprising, incombination, a hollow cylindrical member having a closed end and an openend, and an inlet opening in its side wall, means for directing flow ofair into said opening, a centrally disposed bafile element providing agenerally spiral interior wall surface perpendicular to said closed endand forming with the closed end and side wall of the cylindrical membera substantially annular channel which gradually diminishes incross-sectional area from a maximum at the inlet opening of thecylindrical member, around the member, to a minimum at a point adjacentsaid opening, whereby the air will be discharged substantially equallyat all points around the peripheral rim of the open end of thecylindrical member, and a plurality of baffle plates disposedperpendicularly to the closed end of said cylindrical member and betweenthe centrally disposed baffie element and the outer wall of thecylinder, each of said bafiie plates extending for portions only of thecircumference of the cylinder and conforming to the curvature of thesurface of the baffle element to which it is adjacent, whereby thechannel is divided for certain portions of its length into a pluralityof channels the inner one being of substantially the samecross-sectional area throughout its length while the outer ones diminishgradually to effect the discharge of air at successive arcs around theperiphery of said unit as described.

FRANKLIN L. SLADE.

